TY - JOUR
T1 - The deep water of Eastern Mediterranean Sea is a hotspot for bacterial activity
AU - Rahav, Eyal
AU - Silverman, Jacob
AU - Raveh, Ofrat
AU - Hazan, Or
AU - Rubin-Blum, Maxim
AU - Zeri, Christina
AU - Gogou, Alexandra
AU - Kralj, Martina
AU - Pavlidou, Alexandra
AU - Kress, Nurit
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/6
Y1 - 2019/6
N2 - We investigated the abundance and production of mesopelagic (150–650 m) and bathypelagic (>650 m) bacteria from the poorly-studied Levantine basin (Eastern Mediterranean Sea) during the summers of 2014–2017. We show that the mesopelagic and bathypelagic microbial populations have relatively high cell specific activity, amongst the highest worldwide, likely due to the relatively warm temperatures characterizing these depths in comparison to other oceanic regions. Furthermore, in order to investigate if mesopelagic and bathypelagic microbial populations are limited by the scarce organic carbon substrates in the area, we performed microcosm addition assays of pure glucose (Glu) and/or a mixture of dissolved free amino acids (DFAA). Both the mesopelagic and bathypelagic bacterial populations responded positively to the additions, with bacterial production rapidly increasing within a few hours following the Glu or DFAA amendments. Our results demonstrate that deep-water microbes in the Levantine Basin may be important nutrient recyclers, especially when labile organic carbon is introduced. Our observations may have implications on carbon cycling and sequestration in the oligotrophic Eastern Mediterranean Sea.
AB - We investigated the abundance and production of mesopelagic (150–650 m) and bathypelagic (>650 m) bacteria from the poorly-studied Levantine basin (Eastern Mediterranean Sea) during the summers of 2014–2017. We show that the mesopelagic and bathypelagic microbial populations have relatively high cell specific activity, amongst the highest worldwide, likely due to the relatively warm temperatures characterizing these depths in comparison to other oceanic regions. Furthermore, in order to investigate if mesopelagic and bathypelagic microbial populations are limited by the scarce organic carbon substrates in the area, we performed microcosm addition assays of pure glucose (Glu) and/or a mixture of dissolved free amino acids (DFAA). Both the mesopelagic and bathypelagic bacterial populations responded positively to the additions, with bacterial production rapidly increasing within a few hours following the Glu or DFAA amendments. Our results demonstrate that deep-water microbes in the Levantine Basin may be important nutrient recyclers, especially when labile organic carbon is introduced. Our observations may have implications on carbon cycling and sequestration in the oligotrophic Eastern Mediterranean Sea.
UR - http://www.scopus.com/inward/record.url?scp=85063533785&partnerID=8YFLogxK
U2 - 10.1016/j.dsr2.2019.03.004
DO - 10.1016/j.dsr2.2019.03.004
M3 - Article
AN - SCOPUS:85063533785
SN - 0967-0645
VL - 164
SP - 135
EP - 143
JO - Deep-Sea Research Part II: Topical Studies in Oceanography
JF - Deep-Sea Research Part II: Topical Studies in Oceanography
ER -